Frequently Asked Questions About Ignition Interlock DevicesWhen you’re arrested and charged with a crime, no one gives you a manual about what to actually expect. There’s no pamphlet waiting for you in the back of the cop car titled, “So, Ya Got Caught Driving Drunk.” Aside from your actual legal counsel, you are not actively given much information at all about what you can expect to deal with, how it works, and what you can do about it. That information is passively available to the public on various government websites, but come on. No one is taking the time out of their day to research a bunch of hypothetical legal penalties, and if it’s not hypothetical, they’re too busy being arrested to hop on Google.

If only a super experienced, incredibly knowledgeable criminal defense attorney wrote a nice, easy blog answering a bunch of questions thoroughly and clearly. Golly. What a world.


Ignition interlock devices (IIDs) are something a lot of people know about in theory alone. A good number may only know it by its description rather than its actual name. It’s one of the possible consequences of getting caught driving under the influence, and it is essentially a breath test capable of shutting off your car (or stopping it from starting in the first place) if it senses alcohol. I’m not trying to say this is a confusing concept, but that’s usually the extent people know about these devices — even if they have to get one. So today, I’m going to answer some common questions I get about IIDs, and why you need an Annapolis DUI defrense lawyer like me if you’re facing charges of driving under the influence.

How does an ignition interlock device actually work?

Ignition interlock devices are actually hardwired into your car so they can shut off the engine if it senses a violation. It’s basically a mouth piece connected by a cord to little box that’s wired into the dashboard. You get into your vehicle and breathe into the device, and it allows you to start your car if it doesn’t sense any alcohol on your breath. It also sporadically tests you while you’re driving to make sure you’re not drinking actively once the wheels are moving.

What is the minimum BAC to stop your car from turning on with an ignition interlock device?

.025%. If the device registers a BAC at or above that level at any point, your car isn’t moving. Understand, though, that the .025% still gets recorded, so even though the car starts (more on that in a bit) anyone looking at the data will see you’re not at a .00 BAC.

Can you get in trouble for attempting to drive under the influence, even if the device successfully stops you and you end up getting an Uber?

You sure can. Here’s what the Maryland Motor Vehicle Administration has to say about it:

There are some everyday items that contain small amount of alcohol and may cause the system to record a violation. Medications such as asthma inhalers or medications containing small amounts of alcohol may cause problems as well. The driver will be held responsible if any of these alcohol-based products cause them to violate the system. To prevent this, the Service Provider will instruct you regarding ignition interlock failures and what you can do to avoid them.

So, this is why the IID will still start if there are traces of alcohol in your system, but look at that second to last sentence: “The driver will be held responsible if any of these alcohol-based products cause them to violate the system.” So even if your asthma meds cause you to blow a BAC above .00, you can still get pinged.

This is why IIDs stink. They’re supposed to stop you from drinking and driving, right? And then the device works and you can’t drink and drive, but you can still get penalized for it.

What are the costs associated with ignition interlock devices?

You didn’t think that just because something is court-mandated, it’s court-covered, right? You do in fact have to pay for your ignition interlock device, whether you’re leasing it or buying it outright. This can mean an extra $100 per month in fees for the device, on top of paying to get a specific “ignition interlock license.” If you have multiple cars, you may need to buy a separate device for each of them, too. Maryland does have options for those who may not be able to afford such a thing, but it only does so much.

Are ignition interlock devices more reliable than breathalyzers/Intoxilyzers/Intoximeters?

Uh…no. Prosecutors and law enforcement really don’t want you to know this, but breathalyzers are largely, scientifically known as a “giant flaming hunk of sad bologna.” They are Unreliable. They’re responsible for scores upon scores of false positive reads, even though they’re still used and trusted by officers. Since ignition interlock devices use a similar set up as a breath test device, it’s not unreasonable to expect similar issues, and boy have those expectations paid off. False readings can happen from something as simple as asthma medication. And, if you fail to test yourself when it requires while you’re driving (which happens randomly and with limited timeframes to act within), it counts as a violation no matter how sober you are.

What circumstances lead to someone needing to install an ignition interlock device?

Most commonly, people are required to install these devices only after getting convicted of a DUI of any sort, but you may be ordered to install one if you refuse a breath test. Even though it’s technically your “right” to refuse, the MVA can still force you to pay the price.

Ignition interlock devices may still be preferable to prison or a complete loss of driving privileges, but that doesn’t mean they’re fun, frugal, or fair. You still want to avoid needing them when you can, and if you have one, make sure you’re aware of any fake “penalties” logged by your device. You can and should fight back against any you find — just not alone.

Defending yourself against DUI penalties in Annapolis

Assuming you have only been charged with a DUI and have yet to be convicted of anything, you want to do everything in your power to lessen your charges and sentences. Depending on how you got arrested and what actually happened, you can hire an aggressive criminal defense attorney to assert either your innocence or the arresting officer’s incompetence. In the cases where your charges can’t be completely dropped, an ignition interlock device may indeed be the lesser of two evils, in which case it’s time to be vigilant in more ways than one.

Yes, drive sober. Drive carefully. Don’t try to tamper with the device or remove it or use it as a bong. But also, take it upon yourself to learn as much as you can about your rights and how accidental violations can happen. You and your attorney can defend your lack of fault and fight the violation and any penalties it may incur, but that can only happen if you actually speak up about it.

At Drew Cochran, Attorney at Law, I help people both before and after conviction keep their rights and freedoms protected. Whether it’s by getting charges dropped, sentences reduced, or penalties disregarded, I have the experience you need to really help. As a proud DUI defense attorney, I operate out of Annapolis and Ellicott City, and I’m ready to answer all your questions and give it to you straight whenever you need me. Call me today at 410-271-1892 or use my contact form to get started.

Just remember — Keep Calm, and Call Drew.